A Raman scattering study of GaAs : As films lifted off GaAs substrate

作者：De-Sheng Jiang, Xueping Li, Baoquan Sun, Hexiang Han · 发表于：Journal of Physics D Applied Physics · 年份：1999 · DOI：10.1088/0022-3727/32/6/005 · 被引用次数：21 · 研究领域：Semiconductor Quantum Structures and Devices、Advancements in Semiconductor Devices and Circuit Design、Semiconductor materials and devices

We performed Raman scattering investigations on low-temperature-grown (LTG) films of GaAs that had been lifted off the GaAs substrate. The Raman measurements unambiguously show the effects of excess arsenic on phonon scattering from LTG films of GaAs. The larger downwards shift of the LO phonon frequency for unannealed free-standing films is explained by invoking the elimination of mismatch strain. The Raman signal due to precipitates of elemental arsenic in the annealed GaAs : As films is determined. It is confirmed that the arsenic clusters formed by rapid thermal annealing are mainly amorphous, giving rise a broad Raman peak in the range 180-260 .